Abstract:
Modern smartphone platforms have millions of apps, many of which request permissions to access private data and resources, like user accounts or location. Smartphone users are often unaware of, if not uncomfortable with, many of their permission settings. Nudging is a soft paternalistic approach intended to support users in making more beneficial decisions.

Nudges can be used to raise smartphone users' awareness of the data collected by their apps. Findings of a field study with Android users show that daily privacy nudges not only increase awareness about sensitive data access by apps but also effectively motivate users to switch away from their prior activity to engage in privacy management. Privacy nudges can further be leveraged to elicit privacy preferences with the goal of creating personalized privacy decision support tools. Additional field studies showed that personalized recommendations for permission settings are largely accepted by participants and are perceived as useful and usable. These findings shed light on issues with current mobile permissions and inform the design of more user-friendly privacy solutions.